Uponor/Wirsbo A3030004 controler fuse keeps blowing

bob_48

The fuse blew on my Uponor/Wirsbo A3030004 radiant controller for the first time..  It had a 2 amp fuse in it.  The system is about 4-5 years old.

I replaced the fuse and turned the power back on, after about 15 seconds I heard the zone pump/valve go on, and saw the fuse flash and burn out again.

Just to test it, I replaced the fuse again, this time with a 3 amp fuse (as the controller said dont go higher than a 4 amp fuse).  This time the 3 amp didnt burn out.

I am trying to determine if there is something else wrong that would make this kind of behavior happen.  Would the controler board be bad?  valve/pump? ???

I have the 3 amp in there now so I can get heat...but I want to make sure I am not going to cause other problems.

Thanks,

bob

Al Letellier_21

fuse blows

Something is obviously drawing overcurrent on the fuse. You may have a wiring issue or the zone valve is going bad and pulling too much amperage. A good test meter will help you diagnose the problem.

Paul Pollets

ZCM's

there was a recall on certain zone control modules from Uponor 4-5 years ago. you'd have to check their tech documents to determine if yours is one of the problem units.  Their relatively inexpensive, so replacement is the way to go.

bob_48

Possible problem found

I didnt notice it before but after looking more closely at the manifold I saw that one had a slight drip under on of the valves.  I pulled off the accuator and saw moisture underneat it and some sticky deposits on the valve...possible from the fluid inside (not being just water).

So I believe I probably have a bad valve and/or its accuator or both.   I am going to put a meter on it to verify.  I am also going to put back a 2 amp fuse and take the accuator off the valve that appears to be wet and see if the fuse blows.

Thanks,

bob